521140613 has 4 divisors (see below), whose sum is σ = 595589280. Its totient is φ = 446691948.

The previous prime is 521140591. The next prime is 521140637. The reversal of 521140613 is 316041125.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-521140613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521140313) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37224323 + ... + 37224336.

It is an arithmetic number, because the mean of its divisors is an integer number (148897320).

Almost surely, 2^521140613 is an apocalyptic number.

It is an amenable number.

521140613 is a deficient number, since it is larger than the sum of its proper divisors (74448667).

521140613 is an equidigital number, since it uses as much as digits as its factorization.

521140613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74448666.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 521140613 is about 22828.5043969157. The cubic root of 521140613 is about 804.7326828682.

Adding to 521140613 its reverse (316041125), we get a palindrome (837181738).

The spelling of 521140613 in words is "five hundred twenty-one million, one hundred forty thousand, six hundred thirteen".